Means for controlling the operation of luminescent lamps and other electrical apparatus



Jan. 15,1946. w. FOERSTE 2,392,845

MEANS FOR CONTROLLING THE OPERATION OF LUMINESCENT LAMPS AND OTHERELECTRICAL APPARATUS Filed Sept. 26, 1941 3 Sheets-Sheet 1 I 40 F 1/45 nn c I rn n n v u u u u INVENTOR.

- ML L/AMFOERS TE ATTQRNEY.

Jan. 15, 1946. w FOERSTE 2,392,845

- MEANS FOR CONTROLLING THE OPERATION OF LUMINESCENT LAMPS AND OTHERELECTRICAL APPARATUS 7 Filed Sept. 26, 1941 3 ShG'hs-Sheet 2 INVENTOR.W/LL/AM FOE/P5 rs ATTORNEY.

Jan. 15, 1946. w] FOERSTE 2,392,845

MEANS FOR CONTROLLING THE OPERATION OF LUMINESCENT LAMPS AND OTHERELECTRICAL APPARATUS Filed Sept. 26, 1941 3 Sheets-Sheet 3 147 INVENTOR.

ATTORNEY.

. former, whereby solenoid means alone, or when Patented Jan. 15, 1946TION OF LUMINE OTHER ELECTRIC William Foerste, Pelham Manor, N.

SCENT LAMPS AND AL APPARATUS Y., assignor of one half to Eugene A.Quarrie, Scarsdaie,

Application September 26, 1941, Serial No. 412,492 9 Claims. (01.315-278) The invention relates to the operation of raregas-fllled lampsof the ordinary luminescent type as well as of the fluorescent type,wherein to effect the illumination an electrical discharge is providedbetween electrodes at opposite ends of an envelope containing a suitablegaseous medium. These lamps are usually operated by connecting theelectrodes to the secondary of a transformer, the secondary voltagehaving a high open-circuit value. The transformers, as a rule, areconstructed to have a high reactance, the gaseous tube element requiringa relatively high initial voltage to ionize the contained gas but only arelatively low operating voltage thereafter. Control of the intensity ofillumination has heretofore been attempted by including in circuit withthe primary of the operating transformer large value impedance which, ofcourse, reduces the applied voltage. This results, generally, ininefllcient and unsatisfactory operation of a lamp, particularly due toexcessiveflickering.

It is an object of the present invention to provide means, including ahigh reactance transthe required high initial voltage will be affordedand at the same time variations in the output of the secondary of thetransformer may be effected within the primary circuit to control,

erated from the transformer.

A further object of the invention is to maintain for example, theintensity of the illumination provided by a luminescent tube opvide asimple and rugged construction by embodying the control features as anintegral part of the transformer.

The invention has for an object, also, to provide means in connectionwith the novel transformer arrangement for correcting the power factorand to preserve at the same time against welding, pitting, and generaldeterioration the control contacts employed for varying the output ofthe transformer. 1

In carrying out the invention, there is associated with the usualtransformer core means such as a solenoid or one or more supplementaryor auxiliary cores inviting magneticleakage. Such associated in a novelmanner with a core or cores, directs the flux produced in thetransformer core by the primary winding of the tansformer respondinglythe output of the seconday winding of such transformer. Suitableswitching means to control cor- 7 56 core 20 extends within the maincore are associated with these control or flux-directing windings tosecure the desired output, the

whole arrangement being such, however, that a open-circuit secondaryFig. 2 illustrates a modification in the arrangement.

Fig. 3 illustrates an auto-transformer type embodying the novelarrangement. K Fig. 4 illustrates the. control arrangement formulti-tube operation from a transformer common thereto.

Fig. 5 illustrates a further modification.

Fig. 6 illustrates atom of transformer control similar to that-shown inFig. 1, but provided with a novel arrangement for power-factorcorrection.

Referring to the drawings, more particularly Fig. 1 thereof, 1 0designates the closed core structure of a transformer, which may beconstructed in the usual manner of laminated iron, said core afiording aclosed magnetic circuit. -A primary winding II is provided thereon andderives its power from the main I2 through a lead l3 and a switch-arm I4. 'A secondary winding I5 is also provided on the core, and is shown asconnected directly to the electrodes l6 and I1, either of the hot orcold type. of a luminescent lamp including a transparent envelope I 8.Winding I 5 is thus in inductive relationship to the primary andsupplies the lamp. with the requisite voltage for its proper operation.In the operation of these lamps it is understood that an initially highvoltage must be supplied :by the secondary to effect the ionization ofthe rare gas in the envelope, this voltage then dropping to a much lowersustaining or working value when the lamp is in.

service. The novel arrangement hereinafter set forth, however, affordsat the same time a ballast to prevent overheatingof-the tube anddisintegration of the tube elements, thereby maintaining the currentdensity and the light intensity.

In accordance with the invention, an auxiliary structure to positionindicated afford a high leakage reactance element or magnetic shunt,there being provided over said core a winding divided, for example, intotwo coil portions 2| and 22. As shown, the winding is divided midway tothis end by connection of the lead 23 from the primary ii substantiallyto the midpoint of the said winding. Respective leads 24 r theswitch-point 30. In the latter instance, the

transformer will operate in the usual manner with core introducing acertain amount or reactance due to the normal magnetic leakage providedthereby. However. the amount or this reactance may be respectivelyincreased or decreased accordingly as one or the other or the coils 2|or 22 is energized by setting the switcharm i4 to switch-point 28 orswitch-point 28, re-

spectivelythe one coil being subtractive in its effect, developing anopposing flux, and the other additive, developing a like flux, withrespect to the reactance normally introduced by the core 20.

Tue magnitude of the flux oi the core may thus be varied and while thiswill accordingly vary the current supplied, the open-circuit voltagedelivered by the secondary II remains substantially constant inaccordance with the requirements of the lamp and the relationshipbetween the number of primary and secondary turns. The dimensions or thecore, more especially its length, will be according to the requirementsof the variation desired and the core may be omitted entirely in someinstances and merely the solenoid utilized. The leakage eflectoi thecore will then, of course, be missing and only the solenoid is effectiveto provide for leakage and in accordance with the current flowing in theprimary winding.

This particular type of control lends itself, also, to the production orflasher apparatus or light beacons and in which it is possible,moreover, to provide automatically consecutive illuminations ofdiflerent intensities. For example, a thermostatic circuit-controilingdevice 35 may be included in series in a circuit across the contactpoints as and 8D, and there is included in the two leads 38 and 31 ofsaid circuit a switch 38 whereby the eflect of the thermostatic devicemay be introduced or dispensed with accordingly as the switch 38 closesthe circuit or opens the same. When the switch 38 is in the closedposition, and the contact 88 of thermostatic device 35 also is inposition to close the said circuit at this contact, one of the windingson core 2! is by-passed and opposes the core flux. The current suppliedto the secondary l5 and the lamp connected thereto will thenbe or oneintensity, switch-arm i4 having been moved first to the in the brokenlines, on switchpoint 2!. This connects the primary Ii directly with thesupply main l2; and current flowing through the leads -21 willeventually cause the thermostatic device to operate to open saidby-passing circuit at the contact as thereof.

This latter circuit is then ineilective and the current to the primaryii must also now through aselected one! the windings on cos-e20, in thepresent instance the winding 2|. This will afford v a secondary currentof a diflerent value with corresponding change in the light intensity ofthe lamp.

Various combinations, of course, are possible by providing for diilerentconnections oi the ther mostatic device to other switch-points, as willbe readily understood; and in instances where the auxiliary or leakagecore contains but a single winding, a simplified arrangement becomespossible involving cutting out merely such winding alternatively withits inclusion with the primary. Fig. 2 illustrates an additional form oftransformer construction in which the main core structure includes across-core 40 upon which the primary winding 4| as well as the secondarywinding 42 are located. In addition, two auxiliary cores or high-leakagereactance elements 43, 44 are provided extending midway of thetransformer structure toward the cross-core 40. Each one of these lattercores 43 and 44 is provided with a corresponding winding 45 and 46,respectively, which are arranged to be placed alternatively in circuitwith the primary winding 4!. This may be effected by the switch-armconnected to one lead Ill of the supply main 52, the other lead 58 beingconnected directly to one terminal of the primary winding 4|. The otherterminal of said primary winding is connected through lead 54 to aswitch-point 55, as well as to one terminal of the winding 46 whoseother terminal is connected through lead 58 to a switch-point 51. Thislatter terminal of the winding 46 also is connected to one terminal oithe winding 45 whose other terminal is connected through lead 58 toswitch-point 59.

In accordance with the position of arm ill with respect to theswitch-points 55, l1, and 59, various currents will be supplied tosecondary winding 42 for illumination of the lamp 60 at diflerentintensities.

An auto-transformer arrangement is indicated in Fig. 3 as equipped withthe current-modifying circuits hereinbetore described. As shown, aprimary winding 84 red from the main through leads 66 and O1 energizesthe secondary comprising the separated halves 88 and 69 which ailord thesupply current to energize lamp 10. A condenser -'|l across thesecondary. minimizes the power factor loss of the power supply device,as well as facilitating starting.

A switch-arm 12 when positioned on the switchpoint 13 eiiects thisdirect connection of main 85 with the primary 64, other switch-points 1455 and I! being provided for ailordingdiflerent current values as set upin the secondary coil 8-H. For example, two auxiliary cores l6 and 11,alfording high leakage reactance, are provided with correspondingwindings l8 and I8, respectively.'

One terminal of the former winding is connected to the lead 88. theother terminal of said winding being connected by lead with theswitchpoint 14. This lead 84 is also connected with one terminal of thewinding 19 whose other terminal is connected by lead 8| with the switchpoint II. when the switch-arm I2 is positioned on switch-point 14, onlythe winding II will be effective to alter the secondary output; whereas,when located on the switch-point Ii, both windings II and I! will beincluded in series with the primary winding 04. It the windings It, I!be arranged such that the direction oi ilow will eilect magnetization ofthe respective cores in opposition to the leakage elects, a regulatingeiiect on the tube supply current results which ment of an additionalrectifier I31.

primary circuit of transformer I26 is energized prevents overheating andresultant rapid destruction of the said tube.

In Fig. 4 is indicated an arrangement for multiple-lamp operationsimultaneously and in a like amount by the secondary output variations.vThe ture, but the windings thereon are diflerently arranged from thoseindicated in Fig. 3 for the corresponding elements.

Each core 90 and 91 is provided with a double winding, the former havingthe windings I and IOI, and the latter the windings I0'2.and I03. Theparticular switching arrangement in this embodiment includes thedouble-pole switch-arm I04 and the corresponding sets of switch-pointsI05, I06, 101, and I08, I09, IIO.

When arm I04 isin the position indicated, the light of one of the tubes94, 96 is dimmed and of the other intensified; and when moved to theposition indicated by the broken lines, the reverse action takes place.In the intermediate position, viz: when the points I06 and I09 arebridged by the arm I04, both tubes operate at the same intensity. Underall the conditions, the primary load,'however, remains substantiallyconstant, which is not the case in the embodiments herelnbeforedescribed. I

In Fig. 5 there is illustrated a further modification in the flasherarrangement of control and wherein the modified illumination efiect isimparted gradually rather than instantaneously at its full value. Thus,lamp I I5 is operated from the secondary II6 of transformer II1 whoseprimary H8 is connected to the main II9. There is provided, also, anauxiliary leakage core I with the two windings I2I' and I22 thereonwhose efiects on the core are additive. These windings are. arranged tobe energized automatically through a circuit I23 including athermostatic device I24 energizing the primary winding I25 of atransformer I26. There is included in this circuit, also, a ballastresistance I21 fair the purpose hereinafter set forth.

A lead I connects the mid-point,'for example, of the winding on, coreI20 to'on'e lead of the main H9 and from the other lead of the main alead I 3| is connected to a secondary winding I32 on the transformerI26. The respective ends of the windings I2I and I22 are connectedthrough lead I33 to another secondary winding I36 of transformer I26 andto the plate of a thermionic rectifier I 34 through a lead I35. The

of the two rectifiers increase, their resistances correspondinglyincrease, resulting in lesser primary current flow in transformer I26and reduced voltage drop across the ballast resistance I21. Initially,this resistance serves to reduce materially the current flow through thecold filaments and thus cause the variation inlight intensity of lamp Hito be applied gradually.

Apparatus of the nature hereinbefore set forth may readily be correctedfor power factor loss i by bridging a condenser across the primary coiland associated auxiliary core winding. As indicated inF'ig. 6, thetransformer I40 is provided with'a primary MI and secondary I42 whichenergizes the lamp I43. The auxilary core I44 carries the winding I45from which a tap is taken through lead I46 to one electrode of acondenser I41, the other electrode being connected through lead I48 to atap I49 of the primary. By this expedient,these taps, in providing anincreased voltage, allow ofthe us of a smaller capacity condenser.Moreover, the tap portions may be in the nature of bufier coils tomomentarily check the surge of condenser discharges on closing of thecircuit through a switcharm I50 to the switch-points I5I and I52,thereby obviating welding of the arm to a point.

I claim:

1. The combination with a luminescent discharge lamp of the gas-filledtype operating at a substantially constant ionization voltage; of meansto vary at substantially constant opencircuit voltage the power suppliedto the lamp to'alter the intensity of illumination thereof, including atransformer having a closed magnetic core, only one primary and at leastone closely coupled secondary connected to the lamp; and a highreluctance variable reactor in single-acting shunt magnetic relationshipwith said core and including a coil in series with the primary, saidreactor being magnetically positioned between the primary and secondaryand separated from the core by a non-magnetic gap to invite magneticleakage and to divert flux from a portion of said core.

2. 'I'hecombination with a luminescent discharge lamp of the gas-filledtype operating at core, only one primary and at least one closelywindings I32 and I36 serve to energize respectively the filament ofrectifier I34 and the fila- When the a substantially constant ionizationvoltage; of means to vary at substantially constant open circuit voltagethe power supplied to the lamp to alter the intensity of illuminationthereof, in'-' cluding a transformer having a closed magnetic coupledsecondary connected to the lamp; a high reluctance reactor insingle-acting shunt magnetic relationship with said core and including acoil in series with the primary, said reactor being magneticallypositioned between the primary and secondary and separated from the coreby a non-magnetic gap to invite magneticv leakage and to divert fluxfrom a portion of said core; a source of electrical energy supply; andmeans for connecting alternatively thereto either said single primaryorsaid primary' in series with the said reactor.

3. The combination with a luminescent discharge lamp of the gas-filledtype operating at a substantially constant ionization voltage; of meansto vary at substantially constant opencircuit voltage the power suppliedto the lamp to alter the intensity of illumination thereof, in-- cludinga transformer having a closed magnetic core, only one primary and atleast one closely coupled secondary connected to the lamp; highreluctance reactor means in single-acting shunt magnetic relationshipwith said core and magnetically positioned between the primary andsecondary and separated from the core by a nonadapted to divert flux inphase with the transformer flux; a source of electrical energy supply;and switching means for connecting alternatively thereto either thewinding of said single primary or the winding of said primary in serieswith selected taps oi the winding of the said reactor.

4. The combination of claim 1, wherein a means is provided forautomatically controlling the reactor means.

5. The combination claim 3. wherein a circuit is provided forshort-circuiting the reactor means winding, and a circuit-interruptingmeans is included therein.

6. The combination of claim 1, wherein a condenser is connected acrossthe lamp, and an inductance is included between the said condenser andeach terminal of the lamp.

7. The combination of claim 1, wherein a condenser is connected with theprimary and with the reactor means.

8. The combination-o! claim 1, wherein the primary has an auxiliarywinding constituting with the primary winding an autotransiormer, and aconnection is provided from the free end of the auxiliary winding to thereactor means with a condenser included in series in the saidconnection.

9. The combination with a luminescent discharge lamp oi. the gas-tilledtype operating at magnetic circuit, only one primary, and at leastprimary.

WILLIAM FOERS'IE.

